The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A fuel control system controls provision of fuel to an engine. The fuel control system determines target fueling parameters based on a target equivalence ratio (EQR). To reach the target EQR, the fuel control system controls the amount of fuel provided to the engine based on data from one or more universal exhaust gas oxygen (UEGO) sensors. For example only, when a UEGO sensor indicates that the exhaust gas is (fuel) rich relative to the target EQR, the fuel control system may decrease the amount of fuel provided to the engine. Conversely, the fuel control system may increase the amount of fuel provided to the engine when the exhaust gas is lean relative to the target EQR. Adjusting the amount of fuel provided to the engine based on UEGO measurements modulates the air/fuel mixture combusted within the engine at approximately the target EQR (e.g., a stoichiometric EQR).